1. Field of the Invention
This invention relates to a motion picture camera, and more particularly, it is concerned with control devices for such motion picture camera effecting various photographic modes depending on necessity.
2. Description of Prior Arts
The motion picture camera available at present is generally provided with an automatic exposure control device. In such motion picture camera having the automatic exposure control device, the operating conditions of the automatic exposure control device should be placed in a stable operating conditions in advance of film transport by a film feeding device. The reason for this is that, when the film feeding is started for photographic operation in a state of the exposure control device being still unstable, the exposure of the film is inappropriate until the exposure control device becomes stablized. In a camera of a type, wherein the exposure control device is operated simultaneously with actuation of the motion picture camera, such inappropriate photographic result is brought about at every actuation of the camera, which is not favorable. For this reason, there has so far been proposed a motion picture camera which is so constructed that electric current flows into the exposure control device simultaneously with closure of the main switch to actuate the camera, and subsequently, when the trigger operating member is actuated, electric conduction is effected to the film feeding device so as to carry out the film feeding operation. While this construction can avoid such problem that extremely inappropriate photographic operation is performed, since there unavoidably exists a delay due to sequence of operation between closure of the main switch and actuation of the trigger operating means, and, when the trigger operation starts, the exposure control device has been brought to its stable operating condition, it is still not free from another problem such that waste in power consumption occurs when the main switch is foregotten to be disconnected in case of no photographic operation being done, because the current constantly flows through the exposure control device. As a solution to this problem, the method adopted in the conventional motion picture camera is that the trigger operation is performed in two stages. That is to say, delay in the operating strokes in the trigger operation is utilized in such a manner that no current flows through the exposure control device when the main switch is merely closed, but it flows therethrough when the trigger operating means is slightly actuated and the operation of the exposure control device is commenced, and when the trigger operating means is further actuated, the current then flows through the film feeding device to cause it to commence the film feeding operation. When such construction is adopted, no electric conduction is effected to the exposure control device unless the trigger operating means is actuated, even when the main switch is merely closed, hence there is no possibility of waste in the power consumption even if the camera is left as it is without turning off the main switch. However, this method is still not free from the problem. That is, since this latter method takes the timings for the power supply to both exposure control device and film feeding device by the operating strokes of the trigger operating means, if the trigger operating means is actuated too abruptly, the photographic operation starts with the exposure control device still being unstable in its operation, on account of which the photographic operation under inadequate exposure is resulted. Accordingly, it is desirable to have a cine camera of a construction such that no electric conduction is effected to the exposure control device with mere closure of the main switch, but such electric condition can first be effected by actuating the trigger operating means, and that, when the trigger operating means is actuated, there is automatically produced a delay time between commencement of electric conduction to the exposure control device and commencement of electric conduction to the film feeding device to actuate both devices sequentially.
Moreover, in the motion picture camera existing at present, there is the so-called sound motion picture camera capable of using both "silent film" which can record picture alone and "sound film" which can record both picture and sound simultaneously. This sound motion picture camera includes an intermittent film feeding device to intermittently feed the film at a picture image recording location, where the film is exposed, a continuous film feeding device to continuously feed the film at a sound recording location a sound recording device having a magnetic head to record sound signals on the film at the sound recording location, a loop sensor device to detect a film length between the picture image recording location and the sound recording location, and others. In this type of motion picture camera, the operations should be carried out so regularly and sequentially that electric supply may first be supplied to the sound recording device, while care is taken not to apply an output from the sound recording device to the magnetic head, then the continuous film feeding device may be actuated with simultaneous supply of the output from the sound recording device to the magnetic head, and subsequently the intermittent film feeding device may be actuated. If this operating sequence becomes inversed, in particular, if the operating sequence of the continuous film feeding device and the intermittent film feeding device becomes reversed, the film length between the picture image recording location and the sound recording location increases abnormally at the start of the photographic operation with the consequent occurrence of a problem such as jamming of the film within the camera.
In the heretofore known sound motion picture cameras, however, the start of the continuous film feeding device and the intermittent film feeding device depends almost entirely on a switching device which is turned on and off by a mechanical displacement caused by depression of the trigger operating means, hence its operation is extremely uncertain and unstable. Besides the above, the sound motion picture camera requires the following series of operations.
(1) "on" and "off" controls of the switch to effect electric condition to the exposure control circuit;
(2) setting of the loop sensor to a predetermined position;
(3) setting of a film guide member to the magnetic head disposed at the sound recording location so as to prevent sidewise deflection of the film during its forwarding operation;
(4) setting of a head pad to press-contract the magnetic surface of the film to the magnetic head;
(5) setting of the pinch roller to be press-contacted to the capstan;
(6) "on" and "off" controls of the switch to effect electric conduction to the motor circuit for driving the capstan;
(7) "on" and "off" controls of the switch to effect electric conduction to the motor drive circuit to operate the intermittent film feeding device at the picture image recording location after a predetermined time of the switch operation for effecting the electric conduction to the motor circuit to drive the capstan; and
(8) switch control for feeding the output from the sound recording device to the magnetic head after the capstan driving motor and the intermittent film feeding device driving motor have reached their normal speed.
By the abovementioned series of operations being done sequentially and regularly, the normal film feeding and recording operations can first be realized. However, in the conventional sound motion picture camera which carries out these series of operations through depression of the trigger operating means, an operator should press such trigger operating means by his finger, the force of depression required of his finger being several kilograms, or so. Therefore, maintenance of such large amount of depressing force to the trigger operating means during the photo-taking operation causes considerable labor and hardship to the operator. On account of this, the operator gets very tired of his continuous pressing of the trigger operating means during the photo-taking operation, hence there frequently occur troubles such that he unavoidably releases his finger from the trigger operating means, and so on.
In addition, number of cinematographic enthusiasts is increasing nowadays, along with which increasing number of people adopt very special cinematographic techniques. In this consequence, it has been desired that a motion picture camera having functions of performing such special cinematographic techniques would appear. Such special cinematographic techniques are, for example, fade-in and fade-out operation of picture image, fade-in and fade-out of voice alone, fade-in and fade-out of both picture image and voice, overlapping of picture images alone, self-timer operation, single frame operation, interval timer operation, and so forth. There has so far existed a motion picture camera, in which some of such special techniques can be practiced, but not a single camera has ever appeared, in which all these special techniques as abovementioned could be performed in it. The reason for this is that, if the motion picture camera is constructed with a greater combination of these individual special techniques, the constituent elements of each control device in the camera becomes complicated and, moreover, cause logical contradiction among these elements, and that when the camera is constructed ignoring these problems, not only large space for arranging these control devices becomes necessary accompanied by increase in the overall outer size of the camera, but also the number of the operating means to operate each control device increases to inevitably cause the camera operations to be cumbersome.